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The UK government’s Soft Drinks Industry Levy (SDIL), introduced to help tackle childhood obesity and related conditions such as diabetes and heart disease, has resulted in UK soft drinks manufacturers lowering the sugar levels in their drinks. 

The SDIL was introduced on 6 April 2018, and applies to drinks containing more than 5g of sugar per 100ml, but not to fruit juice, milk-based drinks, alcoholic drinks, or drinks from companies with sales of less than 1m litres per year. 

The first direct evaluation of the effects of the SDIL on drink formulation has found that the changes brought about by the SDIL have been far greater than those achieved by voluntary industry initiatives. Results showed that by February 2019, just 15% of eligible drinks were liable for the levy, compared to 52% of eligible drinks liable when the levy was announced. 

The research, published today in PLoS Medicine, was led by Associate Professor Peter Scarborough and conducted by teams at the University of Oxford, University of Cambridge, London School of Hygiene & Tropical Medicine, Exeter and Bath Universities. 

Sugary drinks taxes are a key measure recommended by the World Health Organization to tackle obesity and related health conditions, and the new analysis shows that such fiscal interventions can be an effective way to improve the population’s diet.

Dr Scarborough said: ‘It is vital that public health interventions are evaluated using robust methods so that we can discover what is effective at preventing ill health. The levy is an important policy as it both reduces the sugar level of many drinks and increases the prices of high sugar drinks, helping the public to make healthier choices. These population approaches are important not only for preventing disease but also for reducing health inequalities.’ 

The researchers assessed a dataset of soft drinks available in UK supermarkets from September 2015 to February 2019. There was already a slight downward trend in the sugar content of drinks before the SDIL was announced. The researchers compared the sugar content of drinks to that background trend, as a measure of how much the SDIL had affected drinks formulation. 

After the announcement of the SDIL the percentage of drinks liable for the levy began to reduce faster than the background trend. The biggest changes in drink formulation occurred just before the implementation of the levy. In the 100 days either side of the implementation date 11% of the eligible drinks reduced sugar content so that they were not liable for the levy. 

Supermarkets had been reducing the sugar content of own brand drinks before the levy, so the changes were less dramatic than for branded drinks when assessed separately. 

Price analysis showed that, for branded drinks, around half of the levy was passed on to consumers in increased prices for drinks in the higher levy category after the SDIL was introduced, while lower levy drinks reduced in price. 

Dr Scarborough concluded: ‘This research provides robust evidence that taxes can be used to improve the healthiness of food, and that they have a bigger influence on the food industry than voluntary measures, such as the government’s public health responsibility deal, or other non-fiscal interventions such as food labelling. The levy is applied to a relatively small proportion of soft drinks, and policymakers should consider extending it to drinks that are currently exempt, such as milk-based drinks.’


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